Magnetic latch mounting



Nov. 4, 1969 P. J. WALKER 3,476,428

MAGNETIC LATCH MOUNTING Filed Jan. 8, 1968 INvEN'roR PATRICK J. WALKER 6 1M 4 MIAMI, 4%; COM

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United States Patent 3,476,428 MAGNETIC LATCH MOUNTING Patrick J. Walker, Chicago, 11]., assignor to Kinkead Industries Incorporated Filed Jan. i 1968, Ser. No. 696,403

I Int. Cl. Ec 19/16 US. Cl. 292-251.5 I Y ABSTRACT OF THE DISCLOSURE DESCRIPTION on THE INVENTION This invention relates generally. to magnetic door latches and more particularly concerns a magnetic latch especially suited for a shower door.

Shower doors are normally manufactured so as to be suitable for enclosures of varying size, and are designed so that no great precision in installation is required. As one result, the edge members which come together to close such doors are not always perfectly alined and, in fact, they are often floatingly supported so as to permit some skewing and thus avoid binding of the door in its track members. v v

A magnetic latch is particularly attractive for a shower door whose closing panel or panels are somewhat resilient and must be held in position. Such a latch needs only pressure in the normal directions to open and close the door, and avoids the need for fumbling with a latch actuating mechanism.

However, for a magnetic latch to be effective, there must be good contact between the magnet and the armature and, as was pointed out above, accurate alinement of the parts being closed is not a characteristic of shower doors.

Accordingly, it is the primary aim of this invention to provide a reliably strong magnetic latch well suited for shower doors. In more detail, it is an object of the invention to provide a latch of this kind that develops a powerful gripping force from a strong magnet by embodying a novel, floating, self-alining mounting for the latch parts.

Another object is to provide a latch of the above character which, while self-alining, is held solidly against locking and unlocking forces and which requires no lubrication or other servicing to maintain its self-alining movement.

A further object is to provide a latch of the above type which is inexpensive to manufacture both because the components can be economically formed and because the latch is easy to assemble.

It is also an object to provide a latch as characterized above which is neat and unobtrusive in a door assembly.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:

FIGURE 1 is a horizontal section taken through a door having a latch constructed in accordance with the present invention;

FIG. 2 is a fragmentary side elevation of one of the elements shown in section in FIG. 1;

FIG. 3 is an exploded fragmentary elevation of the other one of the edge members shown in FIG. 1;

- 2 Claims 3,476,428 Patented Nov. 4,, 1969 FIG. 4 is an exploded perspective of the magnet portion of the latch shown in FIG. 1;

FIlgrIG. 5 is a plan view of the magnet retainer shown in FIG. 6 is a side elevation of the retainer shown in FIG. 5; and

FIG. 7 is an enlarged section through the latch of FIG. 1 showing the parts in a different operating position.

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the inventionto that embodiment. On the contrary, I intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

Turning to the drawing, there is shown in FIG. 1 a pair of edge members 11 and 12 releasably held by a magnetic latch 15 constructed in accordance with the invention. In the illustrated embodiment, the members 11, 12 are vertical, box-like stanchions defining the two closing edges of a double panelled shower door 16 mounted for sliding movement to both the left and the right as seen in The member 11 includes a front facing extrusion 17 formed with a groove 18 holding the edge of a flexible panel 19, and a rear facing extrusion 21 formed with a handle portion 22. Along one edge, the extrusions 17, 21 are locked together by a tongue-in-groove connection 23 and, along the other edge, vertically spaced sheet metal screws 24 and plastic expanding nuts 25 secure overlying flanges 26 and 27, and thus hold the extrusions solidly together. Similarly, the edge member 12 includes a front facing extrusion 31 with a groove 32 holding the edge of a flexible panel 33, and a rear facing extrusion 34 having a handle portion 35. As are the extrusions 17, 21, the extrusions 31, 34 are held together by a tongue-in-groove connection 36 and sheet metal screws 37 cooperating with expanding nuts 38 which secure together overlying flanges 39 and 41. The extrusion 34 also carries a lapping flange 42 arranged to overlie the edge of the member 11 when the door is closed.

The latch 15 includes a magnet 45 on the member 12 and an armature 46 on the member 11. The armature 46 takes the form of a simple steel plate held by one of the screws 24 against the flange 27 and between the edges of the extrusions 17, 21 so that the armature plate cannot turn on the screw. In the preferred construction, the extrusions making up the members 11, 12 are formed of aluminum and hence are non-magnetic, and the armature plate 46, being steel, locks against the magnet 45.

In accordance with the invention, the magnet 45 is formed of a pair of pole pieces 47 sandwiching a magnetized core 48 to form an assembly which is held by a retainer 50 for limited pivoted and tilting movement so that the edges of the pole pieces 47 abut the armature plate 46 when the door 16 closes. Preferably, the pole pieces 47 are flat, square, steel plates and the core 48 is a flat, square body of sintered ferric compound capable of being, and having been, strongly magnetized. The pieces 47 and the core 48 are formed with alined, centrally disposed holes 51, and the retainer 50 includes a mounting pin 52 that passes freely through the holes 51. The pole pieces 47 can thus rotate and tilt with respect to a right angled disposition on the pin 52. Moreover, only magnetic attraction holds the pieces 47 to the opposite side-s of the core 48 so that the pieces can slide on the core to skew the magnet (see FIG. 7) and thus accommodate substantial misalinement between the edge members 11, 12.

As a feature of the invention, the retainer is formed as a one-piece part of flexible plastic which has good moisture resistance and a low coefficient of friction, such as polypropylene. The retainer 50 includes a pair of walls 53 and 54 joined by a connecting strip 55. The pin 52 is formed integrally with the wall 53 and, when the walls 53, 54 are folded about the pole pieces 47, the pin 52 is received in a hole 56 formed in the Wall 54. When in assembled relation, the pole pieces 47 thus pivot on the plastic pin 52 between the two plastic walls 53, 54.

The magnet 45 is mounted in place without additional fastenings. The extrusions 31, 34- are formed with internal ribs 57 and 58, respectively, as are the extrusions 17, 21 of the edge member 11. The walls 53, 54 of the retainer 50 are proportioned to fit snugly between the stanchion flanges 39, 41 and the facing internal ribs 57, 58, and the sandwich of the core 48, the pole pieces 47 and the retainer walls 53, 54 is just thick enough to hold the walls 53, 54- in position when the extrusions 31, 34 are joined to form the edge member 12. The stanchion flanges 39, 41 and the internal ribs 57, 58 are notched at 59 to freely receive the pole pieces 47 and thus permit the limited tilting, pivoting and skewing movement of the magnet described above.

It can thus be seen that a strong magnetic latch has been provided by the construction of the invention. The pole pieces 47 readily dispose themselves so as to abut and firmly hold the armature 46, even though there is some misalinement between the edge members 11, 12. The magnet 45, in effect, floats on the member 12.

Since the magnet pole pieces 47 are supported on and between plastic parts, they move freely and do not require lubrication or servicing to maintain their free floating action.

Finally, those skilled in this art will appreciate that the parts of the latch 15 are quite inexpensive to form and assemble so that the construction is well suited to economical mass manufacture. The resulting installation provides a neat, unobtrusive magnetic latch in a door assembly.

I claim as my invention:

1. A magnetic door latch for holding together a pair of edge members comprising, in combination, an armature fixed on one of said members, a magnet on the other of said members, said magnet being formed of a pair of pole pieces sandwiching a magnetized core, said pole pieceseach having an edge adapted to abut said armature when said members are latched, said pole pieces and said core having alined centrally disposed holes, a retainer for said magnet, said retainer including a mounting pin passing freely through said lined holes so as to pivotally and tiltably mount said magnet, said other edge member being formed of aluminum extrusions forming a box-like stanchion with internal ribs, said stanchion and ribs being notched to freely receive said magnet, and said retainer being proportioned to snugly fit within said stanchion and between said ribs so that the magnet is mounted with no other fastening device.

2. A magnetic door latch for holding together a pair of edge members comprising, in combination, an armature fixed on one of said members, a magnet on the other of said members, said magnet being formed of a pair of pole pieces sandwiching a magnetized core, said pole pieces each having an edge adapted to abut said armature when said members are latched, said pole pieces and said core having alined centrally disposed holes, a retainer for said magnet, said retainer including a mounting pin passing freely through said lined holes so as to pivotally and tiltably mount said magnet, said retainer being formed of flexible plastic and including a pair of Walls sandwiching said magnet and mounting each end of said pin so that said magnet pivots and tilts on and between plastic surfaces, said retainer being formed in one piece with a flexible connecting strip between said walls.

References Cited UNITED STATES PATENTS MARVIN A. CHAMPION, Primary Examiner E. J. MCCARTHY, Assistant Examiner 

